A bulk depalletizer is an apparatus that removes objects, for example bottles from a stack of objects on a pallet and transfers the objects to an accumulator table. From the accumulator table the objects can be conveyed to a downstream station where the objects are further processed.
For apparatus that depalletize relatively heavy objects, for example glass bottles or liquid filled glass bottles, the apparatus has a specific construction that enables the apparatus to lift a two-dimensional array of glass bottles vertically from the stacked bottles on a pallet, horizontally transfer the lifted two-dimensional array of glass bottles from the stack of bottles on the pallet to a position over an accumulator table, and then vertically lower the two-dimensional array of glass bottles onto the accumulator table.
Depalletizer apparatus of the above type have been developed with bottle row gripping assemblies that have long, tubular, air impervious bladders. In operation of the apparatus, pairs of deflated bladders are positioned on opposite sides of each row of bottles in the two-dimensional array of bottles at the top of the stack of bottles. The pairs of bladders are then inflated. The inflated bladders on the opposite sides of each row of bottles engage against the opposite sides of the row of bottles and grip the row of bottles between the pair of inflated bladders. The inflated pairs of bladders are then lifted, lifting the two-dimensional array of bottles from the top of the stack of bottles on the pallet. The inflated pairs of bladders are then moved horizontally to move the lifted array of bottles from over the stack of bottles and to position the lifted array of bottles over an accumulator table. The inflated pairs of bladders are then lowered to position the lifted array of bottles on the surface of the accumulator table.
Depalletizing apparatus of the type described above are disadvantaged in that a substantial supply of air is needed to fully inflate the pairs of elongate bladders on the opposite sides of the rows of bottles with sufficient pressure in the bladders to firmly grip the rows of bottles between the pairs of bladders when lifting and transferring the heavy glass bottles.